This K23 career development award will help the PI achieve his long-term career goal to become an independent clinical investigator developing innovative treatments to address health behavior change (including smoking cessation) and mood management in medical populations. As a first step into this research area, the proposed study will focus on cardiac patients who smoke. This award will build on the PI's emerging expertise in Behavioral Activation (BA), a well established, empirically supported treatment for depression that has recently shown promise for enhancing smoking cessation outcomes. Having developed a proficiency in BA for depression, the current K23 application will extend the PI's work to target smoking cessation in patients hospitalized for Acute Coronary Syndrome (ACS). Success in this new research area will require additional mentored training and research experiences. The highly structured training plan in the current application is ideally suited to allow the PI to conduct the proposed research plan (see below) and move towards his long-term career goals. The training plan will provide the PI with knowledge and skills regarding 1) development of theory-based, tailored treatments, 2) design and execution of Randomized Controlled Trials (RCT), 3) advanced statistics, 4) behavioral cardiology, and 5) manuscript preparation and grant writing. Training will be guided by an expert mentorship team with unique skill sets. Dr. Borrelli (primary mentor) is an expert in the design and testing of health behavior change interventions and has received multiple R01s focusing on smoking cessation among medical populations. Dr. Kahler (co-mentor) has particular statistical expertise in analyzing outcome data from smoking cessation trials and analyzing the relationship between smoking and mood. Dr Arrighi (co-mentor) is a cardiologist with a long history of clinical and research mentorship of cardiology fellows. Additional training will be provided by experts in adapting BA for use with medical patients (Dr. Pagoto, consultant) and smoking cessation in cardiac patients (Dr. Bock, collaborator). The PI will have regular meetings with all members of the mentorship team. In addition, the PI will attend relevant classes, seminars, workshops, and national conferences throughout the proposed award. The occurrence of Acute Coronary Syndrome (ACS; unstable angina, ST and non-ST elevation myocardial infarction) can be conceptualized as a teachable moment, whereby patients may be more receptive to smoking cessation messages. Continued smoking following ACS is an independent predictor of mortality. Depressed mood post-ACS is also predictive of mortality, and smokers with depressed mood are less likely to abstain from smoking following an ACS hospitalization. Thus, a single, integrated treatment that targets both depressed mood and smoking could be highly effective in reducing post-ACS mortality. BA may be an ideal treatment or this population: it can easily integrate both mood and smoking cessation related goals and it focuses on addressing restriction of valued activities, which is common in the post-ACS population. Thus, the overall aims of the current study are to develop a BA treatment manual that integrates smoking cessation and mood management for post-ACS smokers (Behavioral Activation Treatment for cardiac patients who smoke; BAT-CS) and to gather preliminary data on the efficacy of this intervention compared to Standard Care. We will first develop the BAT-CS treatment manual through a series of individual qualitative interviews of both patients who quit and patients who failed to quit smoking following ACS. Next we will test feasibility and acceptability and refine the BAT-CS manual through test cases (N=10). Finally, we will conduct a pilot RCT (N=72) comparing BAT-CS (1 in-hospital session and 4-8 post-discharge sessions) to Standard Care (SC; 1 in-hospital session and 4 mailed packets of printed self-help materials). The primary outcome will be biochemically validated 7-day point prevalence abstinence. Differences in depressed mood, quality of life, and BA mediators will also be compared between conditions. Data produced by this research plan will provide pilot data for submission of an R01 to fund a large scale RCT testing the efficacy of BAT-CS. The proposed training and research plans provide substantial first steps towards the PI's ultimate goal of becoming an independent clinical investigator developing innovative treatments to address health behavior change and mood management in medical populations.